/**
 * Copyright (c) 2011-2016, James Zhan 詹波 (jfinal@126.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.cw.jeeyt.common.utils;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.QuadCurve2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.cw.jeeyt.common.tools.CookieKit;
import com.cw.jeeyt.common.tools.HashKit;
import com.cw.lang.common.log.Log;
import com.cw.lang.common.log.TenantLog;
import com.cw.lang.common.utils.StringUtil;

/**
 * CaptchaRender.
 *
 * @author jfinal
 */
public class CaptchaMaker {
    /**
     * 默认的验证码大小
     */
    private static final int WIDTH = 108, HEIGHT = 40;
    /**
     * 验证码随机字符数组
     */
    private static final String[] strArr = {"3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H",
        "J", "K", "M", "N", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y"};
    /**
     * 验证码字体
     */
    private static final Font[] RANDOM_FONT = new Font[] {new Font("nyala", Font.BOLD, 38), new Font("Arial", Font.BOLD,
        32), new Font("Bell MT", Font.BOLD, 32), new Font("Credit valley", Font.BOLD, 34), new Font("Impact", Font.BOLD,
        32), new Font(Font.MONOSPACED, Font.BOLD, 40)};
    private static String captchaName = "_tframework_captcha";
    private Log log = TenantLog.getLogger(CaptchaMaker.class);
    private HttpServletResponse response;

    private CaptchaMaker(HttpServletResponse response) {
        this.response = response;
    }

    public static CaptchaMaker init(HttpServletResponse response) {
        return new CaptchaMaker(response);
    }

    /**
     * 设置 captchaName
     */
    public static void setCaptchaName(String captchaName) {
        if (StringUtil.isBlank(captchaName)) {
            throw new IllegalArgumentException("captchaName can not be blank.");
        }
        CaptchaMaker.captchaName = captchaName;
    }

    /**
     * 仅能验证一次，验证后立即销毁 cookie
     *
     * @param request
     * @param response
     * @param userInputCaptcha 用户输入的验证码
     * @return 验证通过返回 true, 否则返回 false
     */
    public static boolean validate(HttpServletRequest request, HttpServletResponse response, String userInputCaptcha) {
        if (StringUtil.isBlank(userInputCaptcha)) {
            return false;
        }
        /**
         * 转成大写重要
         */
        userInputCaptcha = userInputCaptcha.toUpperCase();
        userInputCaptcha = HashKit.md5(userInputCaptcha);
        String cookieValue = CookieKit.getCookie(captchaName, request);
        boolean result = userInputCaptcha.equals(cookieValue);
        if (result == true) {
            CookieKit.removeCookie(captchaName, response);
        }
        return result;
    }

    /**
     * 生成验证码
     */
    public void start() {
        BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
        String vCode = drawGraphic(image);
        /**
         * 转成大写重要
         */
        vCode = vCode.toUpperCase();
        vCode = HashKit.md5(vCode);
        Cookie cookie = new Cookie(captchaName, vCode);
        cookie.setMaxAge(-1);
        cookie.setPath("/");
        try {
            // try catch 用来兼容不支持 httpOnly 的 tomcat、jetty
            cookie.setHttpOnly(true);
        } catch (Exception e) {
            log.error(e);
        }
        response.addCookie(cookie);
        response.setHeader("Pragma", "no-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("image/jpeg");

        ServletOutputStream sos = null;
        try {
            sos = response.getOutputStream();
            ImageIO.write(image, "jpeg", sos);
        } catch (IOException e) {

        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            if (sos != null) {
                try {
                    sos.close();
                } catch (IOException e) {
                    log.error(e);
                }
            }
        }
    }

    private String drawGraphic(BufferedImage image) {
        // 获取图形上下文
        Graphics2D g = image.createGraphics();

        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
        // 图形抗锯齿
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        // 字体抗锯齿
        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

        // 设定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, WIDTH, HEIGHT);

        //生成随机类
        Random random = new Random();
        //设定字体
        g.setFont(RANDOM_FONT[random.nextInt(RANDOM_FONT.length)]);

        // 画蛋蛋，有蛋的生活才精彩
        Color color;
        Integer colorNum = 10;
        for (int i = 0; i < colorNum; i++) {
            color = getRandColor(120, 200);
            g.setColor(color);
            g.drawOval(random.nextInt(WIDTH), random.nextInt(HEIGHT), 5 + random.nextInt(10), 5 + random.nextInt(10));
            color = null;
        }

        // 取随机产生的认证码(4位数字)
        String sRand = "";
        Integer codeNum = 4;
        for (int i = 0; i < codeNum; i++) {
            String rand = String.valueOf(strArr[random.nextInt(strArr.length)]);
            sRand += rand;
            //旋转度数 最好小于45度
            int degree = random.nextInt(28);
            if (i % 2 == 0) {
                degree = degree * (-1);
            }
            //定义坐标
            int x = 22 * i, y = 21;
            //旋转区域
            g.rotate(Math.toRadians(degree), x, y);
            //设定字体颜色
            color = getRandColor(20, 130);
            g.setColor(color);
            //将认证码显示到图象中
            g.drawString(rand, x + 8, y + 10);
            //旋转之后，必须旋转回来
            g.rotate(-Math.toRadians(degree), x, y);
            color = null;
        }
        //图片中间线
        g.setColor(getRandColor(0, 60));
        //width是线宽,float型
        BasicStroke bs = new BasicStroke(3);
        g.setStroke(bs);
        //画出曲线
        QuadCurve2D.Double curve = new QuadCurve2D.Double(0d, random.nextInt(HEIGHT - 8) + 4, WIDTH / 2, HEIGHT / 2,
            WIDTH, random.nextInt(HEIGHT - 8) + 4);
        g.draw(curve);
        // 销毁图像
        g.dispose();
        return sRand;
    }

    /**
     * 给定范围获得随机颜色
     */
    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        Integer num = 255;
        if (fc > num) {
            fc = num;
        }
        if (bc > num) {
            bc = num;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }
}




